More civilians in Iraq have been reported missing or captured by gunmen in what has become a rash of abductions of foreigners from nations taking part in the U.S.-led occupation. At the same time, the U.S. military is still trying to put down a Shiite-led rebellion in southern Iraq.

Three days after his reported abduction, there is still no word on the fate of American Thomas Hamill. Employed by Kellogg, Brown and Root, a U.S. contractor, a videotape of Mr. Hamill has surfaced with the Mississippi native speaking only briefly.

"They attacked our convoy," he said.

His captors are threatening to kill him if U.S. Marines do not withdraw from the town of Fallujah. The Sunni stronghold has been the scene of some of the heaviest fighting in Iraq since the war to topple Saddam Hussein more than a year ago.

The number of Americans and other foreigners reported missing or abducted grew Monday.

"We've got two American soldiers that are unaccounted for at this point," said U.S. General Ricardo Sanchez. "We also have seven KBR employees that are also unaccounted for."

All nine have been missing since a U.S. military fuel convoy was attacked Friday west of Baghdad.

Among the foreigners known to be held hostage are three Japanese civilians kidnapped last week. They are being threatened with death unless Japan withdraws its 500 troops from Iraq. But seven Chinese civilians who were briefly taken hostage have now been released. With coalition troops still battling to put down a week-old Shiite rebellion, the Pentagon's top general in the region is now requesting several thousand more troops be sent to Iraq. General John Abizaid says some of the newly trained Iraqi forces have defected to the side of the militias supporting Shiite cleric Moktada al-Sadr, or have just failed to fight at all.

"In the south, a number of units both in the police force and also in the ICDC [Iraqi Civil Defense Corps] did not stand up to the intimidators of the forces of Sadr's militia and that was a great disappointment to us," he said.

Still, U.S. commanders say they are making progress against the Shiite militias who have been leading an uprising against coalition forces largely in towns in southern Iraq. In the west, a ceasefire was reported generally holding in Fallujah where a week of battles - this time against Sunni gunmen - are reported to have resulted in the deaths of hundreds of Iraqis and most of the more than 40 U.S. Marines who have died in combat in Iraq over the past seven days.

At a news conference in Texas, President Bush alluded to what have been some of the toughest battles in the past year.

"The situation in Iraq has improved," the president said. "But you're right, it was a tough week."

Since the beginning of April, the U.S. military says about 70 coalition soldiers have been killed in the upsurge in fighting and estimates that ten times that number of Iraqi fighters have died.